Study Area and Period
The study participants were recruited from Jimma University, which is a public higher educational institution established in December 1999. Jimma Town is 357 km southwest of Addis Ababa. The university has two institutes and six colleges encompassing a total of 1341academic and 5444 administrative staffs. Evidences show that components of metabolic syndrome such as diabetes mellitus, hypertension and cardiovascular problems are common in the working population (9-10).
Trial design: An individually randomized controlled trial using a parallel design was employed to determine the effect of nutrition and life style behavior change communication (BCC) on MetS and its components.
Participants: Administrative and academic staffs of Jimma University who were involved in the baseline survey (n=704) for developing anthropometric cut-offs (15) were eligible for enrolment into the study. Those who have physical disability including deformity (Kyphosis, Scoliosis), pregnant women, limb deformity that prevents standing erect were excluded.
Sample size: A sample size of 230 was calculated using Gpower 3.0 software assuming an effect size of 0.4 for the mean difference in differences of fasting blood sugar (the commonest component of MetS), margin of error of 0.05, power of 81%, with an intervention to control ratio of 1 and adding 26 for loss to follow up. FBS was used for sample size calculation as it gave the largest sample to have adequate power.
Randomization: The sample was randomly selected from eligible population and allocated to intervention group (those exposed to nutrition and life style behavior change communication) and the control group (those who did not receive any intervention). A simple randomization was done to allocate participants to the intervention (n=115) and control (n=115) arms using ENA Smart software.
Intervention: Six months after baseline data collection, the behavioural change communication intervention continued for three months starting from second half of September, 2015 and up to December 30, 2015. To avoid information contamination the end line data were collected in the first half of September 2015, from the control group and from December 30 to January 15, 2016 for the intervention group. The intervention group was given a face to face behaviour change communication through different strategies including power point presentation for a group of 20 people and facilitated group discussion using evidence on real examples of cases with metabolic syndrome and effective dietary and life style behaviours. The training was delivered every month for three months in Jimma University by the research team members including senior nutritionist, cardiologist, and senior nurses. Each month, the training was given in morning and afternoon sessions for three days with each session lasting for four hours. Each of the intervention group members was given a two page Amharic language brochure to take home after the first training. The study subjects were also reminded the key mottos of the behaviours emphasized during the training through text messages every two weeks, while the control group received nothing before data collection (Table 1). The key messages included : “ your menu should be colourful, avoid the three whites including: fat, sugar and salt, have a diversified diet, aerobic exercise, drink plenty of water, avoid sources trans fats, avoid smoking, avoid khat chewing, avoid unsafe intake of alcohol (≥ 2 drinks per day), have a quality and adequate sleep and avoid sitting for long time”, After the end line data were collected, similar information was given to the control group.
Compliance: Compliance to the intervention was measured through checking the attendances of the monthly training sessions, the number of reminder text messages sent to each person every two weeks and the number of intervention participants who receieved the two page brochure summarizing the training. All the training was given according to the protocol except that two paratcipants missed one and two training sessions.
Outcomes: Primary outcomes of the study are metabolic syndrome and its components including: waist circumference, systolic and diastolic blood pressures, fasting blood sugar, triglyceride levels, high density lipoproteins, total cholesterol and low density lipoproteins. Data collectors who did all anthropometric, clinical parameters measurements and laboratory technologists who did the blood sample analyses were blinded.
Measurements
This study was conducted in accordance with WHO's Stepwise (STEPs) approach for non-communicable disease (NCD) surveillance(16), which is characterized by the use of questionnaires to capture data on risk factors (Step 1): simple physical measurements (Step 2): and biochemical measurements (Step 3) .The STEPs questionnaire was supplemented with additional questions to gather context specific data in the study area. The questionnaire was used to collect data regarding the general socio-demographic characteristics of the population including: age, sex, and education level. Questions included in the behavioural risk factors such as tobacco, alcohol, physical inactivity and Khat consumption (a natural stimulant with amphetamine-like effects commonly used for social recreation in Ethiopia) (17). Experienced research nurses were trained for five days on the contents of the questionnaire, ethical issues and on data collection procedure. All blood sample collections, questionnaire based interviews, anthropometric measurements and blood pressure measurements were done in the laboratory of Department of Nutrition and Dietetics of Jimma University.
Body composition: Body fat percent (adiposity) was determined both at baseline and end line using different anthropometric indices: Body Mass index (BMI) and Waist Circumference (WC). Baseline Body fat percent was measured using air displacement plethysmography (ADP) (life Measurements) following standard procedures (15). Weight was measured with a solar powered scale which was accurate to 100 grams (Model 871, Seca, Germany). Height was measured with an adjustable portable stadiometer which was accurate to 0.1 cm. Waist circumference was measured with a fixed tension tape, at the midpoint between the lower costal margin at the mid-clavicular line and anterior-superior iliac crest (18) in a private place with no clothing on the upper part of the body. To ensure the data quality, Calibration and validation of anthropometric equipments and standardization of anthropometric measurers was done and a coefficient of variation of < 3% was taken as acceptable.
Blood pressure, Lipid Profiles and Fasting blood Glucose: Three blood pressure measurements were taken after individuals had rested for 5 minutes for the first measurement and with a difference of five minutes between successive measurements. In accordance with the WHO recommendation the mean systolic and diastolic BP measurements were considered for analyses. A five ml blood samples was collected from each individual in the morning after overnight fasting using proper sanitation and infection prevention techniques. Serum was used for the measurement of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), glucose concentrations. Details of the methods are published elsewhere (15)
For the end line data, a five ml blood specimen was collected by senior medical laboratory technologist and the serum was separated from the whole blood within 30 minutes and transferred to Nunc tubes and stored in -20 0C refrigerator. After all the specimens were collected, the serum was packed with ice and transported to Mettu Karl Hospital laboratory for determination of lipid profiles using HumaStar 80 (Germany) following standard operating procedures. Fasting blood sugar was determined in Jimma University specialized hospital (JUSH) at JUCAN project laboratory using Humastar within two hours of collection.
Statistical Analyses
Data were doubly entered into Epidfata 3.0 and exported to SPSS for windows version 20 (Inc, Chicago, IL, USA) for cleaning and analyses. The data were cleaned for outliers and missing values before analyses. After excluding a total of six participants (3 interventions and 3 controls) due to loss to follow up and incomplete data (Figure 1) a final sample size of 224 participants ( intervention=112 and control =112) was analyzed. As there were baseline differences in some variables beteen intervention and control groups, difference in differences was employed in all analyses for comparison of the intervention and control arms to determine the effectiveness of the intervention on MetS components. The end line measurements were subtracted from baseline measurements for both intervention and control groups and the differences in differences were compared using independent sample t-test and multivariable linear regression model were used for comparing mean difference in differences. Assumptions including normality, linearity and absence of multi-collinearity and homoscedasticity were checked using Q-Q plots and variance inflation factor.
For the differences in proportions between intervention and control groups at end line chi-square test was used. Multivariable logistic regression model was used to isolate independent predictors of metabolic syndrome at the end of the intervention. For the multivariable logistic regression, multicollinearity and model fitness were checked using standard error <2.0 and Hosmer Lemeshaw test (P>0.05), respectively. Statistical significance was declared at < 0.05.
Operational Definition of Terms
Intervention group – Randomly selected adults who were given nutrition and health life style behavior change communication for three months.
Control group – Randomly selected adults who were not given nutrition and health behavior change communication.
Duration of the intervention: The time during which the life style medication behavior changes communication was given to the intervention group (three months staring from the second half of September 2015 to the December 30, 2015).
Components of Metabolic syndrome based on IDF criteria (20) as follows:
- Raised TG level: > 150 mg/dL (1.7 mmol/L), or specific treatment for this lipid abnormality
- Reduced HDL cholesterol: < 40 mg/dL (1.0 mmol/L) in males and < 50 mg/dL (1.3 mmol/L) in females, or specific treatment for this lipid abnormality.
- Raised blood pressure: systolic BP ≥ 130 or diastolic BP ≥ 85 mm Hg, or treatment of previously diagnosed hypertension.
- Raised fasting plasma glucose (FPG) ≥ 100 mg/dL (5.6 mmol/L), or previously diagnosed type 2 diabetes If above 5.6 mmol/L or 100 mg/dL.
- Central obesity was defined as waist circumference ≥ 80 for women and ≥ 94 for men.
Metabolic syndrome (MetS) is defined in accordance with the IDF as presence of abdominal obesity and three or more MetS components described above (19-20).